copy linked materials nodes to local material
So I finally made it myself again after several hours of playing with the code (see I am actually FLASH ActionScript2 guy so it took me like 2 weeks to understand syntax of Python, its objects etc. and get used to it but now I have fully working script!!!).

The right solution is this:

# ...some quite long code here and now:
for r in _mNews.links: 
    _mOld.links.new(_mOld.nodes[r.from_node.name].outputs[r.from_socket.name], _mOld.nodes[r.to_node.name].inputs[r.to_socket.name])